Heating system

ABSTRACT

A heat exchange system and apparatus comprising: a compressor to compress a refrigerant, a first condenser heat exchanger to which the compressed refrigerant is supplied and at which heat is transferred from the refrigerant to water in a hot water cylinder; an expansion valve that receives cooled liquid refrigerant from the first heat exchanger; a thermodynamic panel including a second heat exchanger heat that receives cool refrigerant from the expansion valve and is in thermal communication with an environmental heat source.

This invention relates to a heat exchange system which is based upon theprinciple of the heat pump.

Solar panel systems are well established devices for transferring theradiant energy from the Sun to other locations, and such panels, ingeneral, also extract ambient heat from their surroundings. However,they are not currently designed and manufactured so as to beconveniently, and flexibly, integrated into existing heating systems.

Known existing systems whose method of operation is based upon theprinciple of the heat pump, have their thermodynamic elements built intothe hot water cylinder, and are not purchasable without the cylinder.This makes such systems very difficult to install, both due to theirsize in comparison with the size of the existing cylinder which is to bereplaced, and with the dimensions of that cylinder's associatedsurroundings. Moreover, these existing systems are also known to belimited to providing hot water at a maximum temperature of 55 degreesCelsius

Thus one current system utilises a so-called, thermodynamic block, whichis built into a hot water cylinder system, but necessitates that thecylinder be 900 mm wide, which consequently renders it difficult toinstall within an existing airing cupboard, or other region of abuilding suitable for the installation of a hot water system.

Consequently, for the system of the present invention, it was decidedthat it would be advantageous to separate the thermodynamic block fromthe cylinder, so that the system would be more flexible with respect toinstallation, and so that it could consequently be placed in a varietyof different locations. A further advantage of the apparatus of thepresent invention is that it can either be connected to an existingcylinder, wherein the existing immersion heater for that cylinder can beretained as part of the new system, or it can be purchased together witha new cylinder.

The present invention also offers the advantage that it provides hotwater at 65 degrees Celsius.

There are various types of heat pumps is the market which absorb heatfrom various sources such as water, ground, stream, outer air, exhaustair and others. In general heat pumps are classified based on where theysource their heat. For example ground source heat pumps get their heatfrom the ground and air source heat pumps get their heat from the air.

Air to water heat pumps currently available in the market make use of asingle unit which is typically located outdoors. The heat pump has anevaporator within their outdoor unit and there is a fan that forces theair through the evaporator to absorb the heat. There is also a condenserto transfer heat to the heating medium which in most cases is awater/glycol mix.

According to the present invention, there is provided a heat transfersystem method, and apparatus, which are based upon the principles of theheat pump, and the Carnot Cycle.

The system allows the heat energy from the Sun, or the radiated,convected, or conducted, heat from the surrounding environment, to betransferred from thermodynamic panels, into the hot water region ofheating systems which utilise other fuels; thereby allowing considerableflexibility in the application of the said system to domestic,commercial, and industrial, hot water systems.

In a first embodiment of the present invention a heat exchanger, allowsrefrigerant to transfer heat from thermodynamic panels, via athermodynamic box, to the hot water inside a hot water cylinderaccording to the operation of the principles of the heat pump.Refrigerant passes through the thermodynamic box under the operation ofa compressor pump, and various controls.

According to the present invention there is provided a heat exchangesystem comprising: a compressor to compress a gaseous refrigerant, afirst condenser heat exchanger to which the compressed refrigerant issupplied and at which heat is transferred from the refrigerant to waterin a hot water cylinder; an expansion valve that receives cooled liquidrefrigerant from the first heat exchanger; a thermodynamic panelincluding a second heat exchanger heat that receives cool refrigerantfrom the expansion valve and is in thermal communication with anenvironmental heat source.

The condenser heat exchanger can have two flow paths in thermalcommunication with each other, a first flow path for refrigerant and asecond flow path for water from the hot water cylinder. Water may bepumped from the hot water cylinder through the second flow path and backto the cylinder by a circulating pump. The condenser heat exchanger maybe a block of thermally conductive material with circuitous flow pathsformed therein.

One or more of an accumulator or receiver, a filter, a drier, a sightglass or moisture indicator, controller and temperature sensors may beprovided as part of the system.

The circulating pump may operates with a with time delay functionalitysuch that it does not start and stop at the same time as the compressoroperates.

The condenser heat exchanger may be orientated in a way to self-drainthe water therefrom as required. Also an air bleed valve assembly may beis provided to remove air from the system.

More than one thermodynamic panel may be connected. A solenoid valve oractuator and control device may be provided to open/close therefrigeration circuit in a second panel or subsequent panel depending onthe conditions.

The second heat exchanger may be a fin-tube evaporator installedoutdoors or outdoors. The evaporator may be part of a combined unit. Afan may be provided to pass air over the evaporator.

The present invention also provides heat exchanger apparatus for use ina system as discussed herein the apparatus comprising the compressor;the first condenser heat exchanger; an expansion valve that receivescooled liquid refrigerant from the first heat exchanger; means to pumpwater to and from the hot water cylinder through the first condenserheat exchanger; and means to connect to the thermodynamic panel inthermal communication with an environmental heat source.

Preferably all the components of the heat exchanger apparatus aremounted inside a single unit or container. This aids retrofitting. Thecompressor and or the single unit may be mounted in such a way as toabsorb or minimise vibration and or to minimise noise.

It will be shown, in the following description, how the presentinvention can be conveniently and flexibly integrated into domestic,commercial, and industrial, hot water systems, thereby giving rise to ahigher level of efficiency in the distribution of heat around buildings,and at reduced cost compared with existing systems.

The operation of the apparatus of the invention is best understood bycomparison with the way in which a refrigerator works, and by way of anintroductory description of the principles of the heat pump:

A heat pump is a device which transfers heat from a source of lowtemperature energy to a region of high temperature, by doing work, andthis is the principle behind the operation of the refrigerator.

Inside the refrigerator, the working fluid (ore refrigerant) is, at onestage in the process, a vapour; a vapour being a gas at a temperaturewhich is below its critical temperature, so that it can be converted toa liquid by the application of pressure alone. This vapour is compressedby means of a compressor pump and, provided that the accompanying changeis adiabatic; and thus takes place without heat entering or leaving thesystem; the temperature of the vapour rises, due to work being done onit by the compressor. It is then passed to a radiator, where heat isgiven out to the surroundings when the vapour condenses to a liquid bygiving up its latent heat of condensation. The liquid is then expandedinto an evaporator which reduces the pressure, and allows work to bedone by the liquid, adiabatically wherein it thus takes in latent heatof vaporisation from the surroundings, and once again becomes a vapour.It is in this region of the refrigerator that cooling takes place. Thecycle is then repeated, by returning the vapour to the compressor, alonga cyclic path.

So, commencing with the evaporation of the refrigerant in therefrigerator, this evaporation is aided by the action of a so-calledcompressor pump, which pumps vapour out of an evaporator which islocated inside the refrigerator, and which consists of several loops ofpipe. This pumping out of the refrigerant vapour, thus reduces thepressure inside the pipe, so that the latent heat required for therefrigerant to evaporate is taken from the air surrounding the loops ofpipe, and, in turn, from the atmosphere, and hence from the food, insidethe refrigerator, so that cooling occurs.

The compressor pump also compresses the refrigerant vapour inside thecondenser pipes of the refrigeration system, which are located on theoutside of the refrigerator, at the rear, and it is here that therefrigerant gives up its latent heat of condensation to the surroundingatmosphere, by a process of radiation and convection.

The flow of liquid refrigerant back into the evaporator is controlled bymeans of a valve, which controls the rate at which heat is removed frominside the refrigerator.

In the apparatus of the present invention, and by comparison with theabove descriptions of the operation of a refrigerator, the coolingeffect which takes place inside the refrigerator, is equivalent to thecooling effect on the ambient environment/atmosphere surrounding thethermodynamic panel, which occurs when refrigerant evaporates inside thepipe network of the panel, and takes in its latent heat of evaporationunder the pumping-out effect of the operation of the compressor pump.

The heat extracted from the ambient atmosphere renders the refrigerantgas hotter than was the refrigerant liquid, and so, the hotter, gaseousrefrigerant, now compressed enters the first heat exchanger which is inlocated inside the hot water cylinder or in thermal communication withwater from the cylinder, and this heat is thus given up to the watercontained within that cylinder.

The now cooler, refrigerant, is in a thermodynamic state known as asaturated liquid, and, after entering a filter, it passes to athrottling device, also known as an expansion valve, where it undergoesan abrupt reduction in pressure, which results in the adiabatic flashevaporation of part of the liquid refrigerant. This, so-called,auto-refrigeration effect which results from the adiabatic flashevaporation lowers the temperature of the liquid and vapour refrigerantmixture, to the extent that it is now colder again, and it now passesback to the thermodynamic panel, wherein the whole cycle is thenrepeated.

The system of the invention can become the primary means for heating thewater, and the existing gas/oil system or any other energy system, canbecome the secondary, and i.e. back up, heat source.

This arrangement will then allow heating of the water, without having toremove the existing cylinder, which is likely to be in satisfactorycondition and not in need of replacement, and this therefore: i) reducescost; ii) reduces wastage; and iii) reduces installation time, frombetween approximately one to two days, to between three to four hours.An additional option, when installing the new system, will be to provideextra insulation to the existing cylinder, by way of a cylinder jacket,in order to reduce heat loss.

A major feature of the new system is that the apparatus (“Magic Box”)will not have to be installed next to the existing cylinder; and can,instead, be installed above it, or in any other workable location, or inthe loft, or garage, or any out building, and the like, wherein thethermodynamic panels can be located away from the cylinder (up to 15metres vertically, and 30 metres horizontally).

If the existing cylinder is replaced, then this offers the advantagethat a cylinder of a size which is comparable with that of the originalcylinder can be installed, and this will be a modern one, provided withgood, and modern, insulation.

The new cylinder can also be provided with a secondary coil, wherein thecylinder and hot water tank are purpose built to contain a heat exchangecoil which transfers heat to the water in the tank.

The thermodynamic panels of the present invention are of such size thattwo, relatively smaller panels, can be installed by one Installer,rather than two. Also, during transport, and when being manipulated bythe Installer, the panels are consequently less flexible, and so arelikely to suffer less damage.

Moreover, by being smaller, there is greater flexibility with respect toinstallation in various locations. Thus, for instance, the panels can beinstalled; i) one on top of the other, or ii) side by side; or iii) oneon either side of a window, etc.

Existing thermodynamic panels are supplied in sizes of 1.9 m by 0.9 m,and 2 m by 0.8 m, whilst the panels of the present invention aresupplied in sizes of 1.4 m by 0.6 m, and 1.0 m by 0.6 m; each having athickness of 5 mm, wherein each of the panels of either size, can beconnected in a side-by-side configuration, or in a one-above-the other,configuration. The weight of a panel which is 1400 mm by 600 mm and is 5mm thick is 4.2 Kg.

The panels may be manufactured from aluminium which absorbs energyefficiently. For strengthening purposes, the panels have an aluminiumalloy reinforcement rib, having ten holes formed around their periphery,for fixing purposes. The technical volume of each panel may be 375 cm³,±10%, and they are suitable for use with refrigerants such as R410A,R134a, R22, R407C and other known refrigerants.

The means of connection the panels to the refrigerant pipe, is viaconventional means such as welding, or the use of brass nuts, usingbraised or flared joints. Depending on the installer and on the natureof the refrigerant gas utilised installation may need to be carried outby a qualified Installer.

The or each thermodynamic panel does not have to be positioned outsideof the premises in which the remainder of the system is installed, andthey can, for instance, be installed in a loft, wherein, due to theaccompanying condensation of water vapour as a consequence of cooling,condensation trays which collect the water, can be provided. This willbe particularly useful if the house/premises, is a listed building,and/or is located in a conservation area, or an area of outstandingnatural beauty. When the apparatus of the invention is installed in aloft, it thus represents an excellent opportunity for recycling heatthat is otherwise wasted in the loft.

The thermodynamic panels can also be buried in the ground, or placed ina lake or other region, of water, or in a tank of water, or in agreenhouse, in order to extract, and transfer, heat.

Other applications can involve the incorporation of the thermodynamicpanels into offices having suspended ceilings, in order to recoverotherwise wasted heat, and yet further applications can involve thepositioning of the panels in a variety of locations in the home; in foodshops; in off licenses; and the like. A range of alternative locationsfor the panels are thus:

-   i) Behind fridges, adjacent to their condenser piping.-   ii) Adjacent to gas cookers-   iii) Adjacent to the ventilation ports on microcomputers-   iv) In the region of swimming pools-   v) Adjacent to the external vents of air conditioning systems, or    similar.

Wherein, all of these applications will aid the recovery of otherwisewasted heat, and will also provide an environmental benefit.

A particular advantage of the invention is that when it is applied torefrigeration systems, there is an accompanying advantage that suchsystems have been in use since the 1950's, and consequently benefit fromtechnological improvements which necessitate minimal maintenance.

The copper tubing utilised for carrying the refrigerant has been tested,for the purposes of ensuring safety, and of satisfying safetylegislation, to a pressure of 240 Bar, without damage; and all pipe runsare well insulated. The copper piping has an outside diameter of 9 mm onentry to the thermodynamic panel, and 16 mm on exit from the panel witha wall thickness which is adequate for safely containing refrigerant.

In order to describe the invention in more detail, reference will now bemade to the accompanying diagrams in which:

FIG. 1 represents a two-dimensional schematic view of the mainfunctional components of a first embodiment of the invention, with somecomponents enlarged.

FIG. 2 represents a three-dimensional schematic view of the mainfunctional components of the invention, with some components enlarged.

FIG. 3 represents a two-dimensional schematic view of two of thethermodynamic panels of the invention in a side-by-side configuration,with one part enlarged. Panels may be connected in other configurationssuch as one-above another.

FIG. 4 represents a three-dimensional schematic view of that componentof the apparatus referred to as the Magic Wand, and also shows how thiscontains both a heat exchange coil, coil and an electric immersionheater element.

FIG. 5 is a schematic view of a further embodiment where water is pumpedfrom the cylinder to interact with the hot refrigerant in aself-contained unit also including the compressor.

FIG. 6 is another embodiment similar to FIG. 5 with a differentthermodynamic panel.

FIG. 7 is a yet another embodiment similar to FIG. 5 with thethermodynamic panel within the self-contained unit. FIGS. 7 a to 7 cshow possible air venting routes.

FIG. 8 shows an arrangement for a gravity fed system similar to that inFIG. 5.

FIG. 9 shows a system with a heat exchange coil in the cylinder andconnected for no direct contact between the hot water and the fluidcirculating around that heat exchange coil to the condenser heatexchanger 2 and back.

With reference to FIG. 1, which represents a two-dimensional schematicview, a heat transfer system, 1, utilises various items of equipment totransfer a refrigerant material around the system, along the pathindicated by the arrows, in order to transfer heat from a thermodynamicpanel, 2, to a thermodynamic block, 3, and thence to a hot watercylinder, 4, and then back again to the panel, 2.

With further reference to FIG. 1, liquid refrigerant inside thethermodynamic panel, 2, is converted to a vapour; which is a gas at atemperature below its critical temperature; and this conversion processextracts, from the panel's surroundings, the latent heat required forvaporisation of the refrigerant. This thus creates a cooling effect onthe ambient atmosphere surrounding the panel, 2, due to the evaporationof refrigerant inside the pipe network of the panel, which is caused bythe pumping-out effect of the operation of the compressor pump, 5, whichis located inside the magic box, 3, and which is acting as an evacuatorat this stage in the process.

Because the hot refrigerant gas is a vapour; that is, a gas which isbelow its critical temperature, it can be liquefied by the applicationof pressure. Because expansion of the refrigerant has occurred, theincrease in volume has to be allowed for, and thus, the compressor pump,5, is connected to a vessel, 6, which provides room in the wholeenclosed system, for the refrigerant vapour, which has increased involume. This vapour can then be compressed by means of the compressorpump, 5, and so that, provided that the accompanying change isadiabatic; and thus takes place without heat entering or leaving thesystem; the temperature of the vapour can rise, due to work being doneon it by the compressor, 5.

The now hot, gaseous refrigerant, is then passed to a heat transfercoil, HTC, generally referred to as a primary heat exchanger coil,which, in this application, is equivalent to the radiator located at therear of a refrigerator, where the latent heat of condensation of therefrigerant is given out, during compression, to the water, W, in thehot water tank, HWT. This thus results in the heating of the water,which circulates through the hot water tank, HWT, after entering at thecold water inlet, CWI, and leaving via the hot water outlet, HWO. Thehot water cylinder, 4, is provided with insulation, INS.

The now cooler, refrigerant, is now in a thermodynamic state known as asaturated liquid. Thus, under the circulatory, pull-push, effect, of thecompressor, the now cooler, saturated, liquid refrigerant, enters afilter, 7, and then passes to a throttling device, 8, also known as anexpansion valve, where it undergoes an abrupt reduction in pressure,which results in the adiabatic flash evaporation of part of the liquidrefrigerant. This so-called, auto-refrigeration effect, which resultsfrom the said adiabatic flash evaporation, lowers the temperature of theliquid and vapour refrigerant mixture, to the extent that it is nowcolder again, and it passes back to the panel, 2, wherein the wholecycle is then repeated, with the now liquid refrigerant able to extractheat from the ambient surroundings, as before, as evaporation occurs.

A display 9 shows the temperature of the hot water in the hot watertank, HWT, via electronic communication with a temperature sensorlocated at that tank.

With reference to FIG. 2, which represents a three-dimensional schematicview, with some components enlarged, this is similar to FIG. 1, butshows additional components. Thus part of the panel, 2, is shown inenlarged form, and tube, M, is just one of the matrix of tubes presentin the panel, 2.

Tube, 10, takes in the cooled, refrigerant, from the outlet of the Block3, and tube, 11, transfers hot gaseous refrigerant to the block 3. Otherparts of the diagram have already been described with reference to FIG.1, and so, need not be described again.

With reference to FIG. 3, which represents a two-dimensional schematicview, this shows two panels, (equivalent to that numbered 2 above butherein referred to as P1, and P2), in a side-by side configuration, withthe region of their means of connection, enlarged. They might be inother configurations such as in a one-above-the-other, configuration.

FIG. 4 represents a three-dimensional view of the Magic Wand of theapparatus, which comprises an outer, heat transfer coil, HTC, and aninner, immersion loop, IL. The heat transfer coil, HTC, containsrefrigerant, which passes into the coil via entrance port, 12, andleaves the coil via exit port, 13. The immersion heater loop, IL, haselectrical contacts with the electrical supply, at terminals, T1, andT2.

This invention can also work on the same initial principle of an air towater heat pump but takes the concept in a further innovative direction.Having the evaporator unit located indoor or outdoor allows theinvention to be installed indoor without need to have glycol in theheating medium.

Installation indoors allows the heating medium to be connected directlyinto the hot water cylinder without the need of an indirect heatexchanger in the cylinder. The invention therefore also allows thetransfer of heat to the hot water with maximum heat transfer capacity.

Air to water heat pumps in the market typically need a heat exchangerinside the hot water cylinder to transfer the heat from the air to waterheat pump into the hot water cylinder via this internal heat exchangerin the cylinder. The main reason for the need of this internal heatexchanger is because of the location of the air to water heat pump whichis normally housed in the outdoor unit which is exposed to the outsideenvironment. Due to the potential freezing problems the heating mediumhas to be a water/glycol mixture to stop the freezing of the heatmedium.

As the heating medium is a water/glycol mixture the design of the systemrequires the internal heat exchanger in the hot water cylinder totransfer the heat without mixing it into the water in the cylinder.

Conversely by heating the water in the cylinder directly without theneed of a heat exchanger allows the invention to achieve highertemperature levels in the hot water cylinder without the need toincrease the condensing pressure and thereby a higher compressorefficiency can be achieved. The invention can also be installed to theheat exchanger coil inside the cylinder as in FIG. 9.

FIG. 5-9 shows various embodiments in which water is drawn from thecylinder and passed through a condenser heat exchanger 2 that forms partof the a single unit 11 including the compressor 1. The compressor whichis electrically driven compresses the low pressure refrigerant from theevaporator unit 13 to increase its pressure and therefore thetemperature. The condenser 2 which receives the high pressure hightemperature refrigerant from the compressor transfers its heat to theheating medium and the refrigerant condenses to become a high pressureliquid.

The Invention also consists of additional auxiliary components which area receiver, filter and drier which can be a single assembly orindividual components. The main function of these components in theinvention is to store the refrigerant in the receiver, remove anyforeign particles through the filter and absorb the presence of anymoisture in the refrigerant with the drier.

Additionally the invention incorporates a sight glass/moisture indicatorwhich enables all the auxiliary components to be monitored as to theirperformance. The sight glass therefore provides vital information to anengineer so he can diagnose the efficient operation of the refrigerationcycle and whether the right amount of refrigerant is in the system. Thesight glass has an in-built moisture indicator which indicates thepresence of any moisture in the refrigerant.

One of the features of the invention is that it heats water in cylinderdirectly. There is a circulating pump 7 within the design of the system.If the hot water in the cylinder is used for domestic use then theinvention will have the pump suitable for the potable water such asbronze body, composite body or other materials which are suitable forpotable water applications.

The condenser 2 includes a plate heat exchanger. The said plate heatexchanger transfers the heat from the high pressure high temperaturerefrigerant in the primary circuit of the heat exchanger to the heatingmedium in the secondary circuit where the heating medium is circulatedby the circulating pump from the hot water cylinder.

The condenser can be a plate heat exchanger made from stainless steel orany other material suitable for hot water applications. It can be ashell-tube heat exchanger where the refrigerant can be passed throughthe tube and the heating medium flows over the tube which sits insidethe outer shell.

The invention incorporates a bleed valve assembly 8 in the watercirculating pipe which allows the invention to remove trapped air thatmay have arisen during the installation or servicing of the system. Thisbleed valve is located in place and orientation that it becomes thehighest point of the water circuit so that the air can be removedeffectively.

This invention having a bleed valve assembly uniquely allows theinvention to be able to be installed in a traditional gravity feedsystem where the pressure in the water circuit can be very low and thepotential problem of air therefore getting trapped in the water circuitis very high and it is very difficult to remove due to the lowerpressure in the water circuit.

The presence of this air in the water circuit can be very hazardouspotentially causes pump cavitation which could lead to higher condensingpressures in the condenser which in turn decreases the efficiency of thecompressor and its life. Inclusion of the bleed valve assembly in theinvention eliminates this potential problem.

This invention also has designed a unique and new plumbing installationmethod to connect the pipe where within all gravity fed hot watercylinders when installing the invention into the system in such a waythat it removes air bubbles in the system through the dual vent pipedesign as per FIG. 8. The dual vent pipes 19 20 are either two separatebranches of pipe going in to the feed tank or the two branches of pipecan be interlinked to have a single pipe going in to the feed tank.

For clarity the feed tank here is generally a vessel which feeds the hotwater cylinder and is normally located in the highest place in the housesuch as the loft. The feed tank receives the water from the main watersupply.

The invention can have a “self-drain” capability in the water circuitcomponents such as the plate heat exchanger which is the condenser,water circulating pump and the pipe works connecting all of thesecomponents. This is achieved by positioning and locating the componentsin such a way within the design of the invention such that the watercircuit drains itself naturally.

This eliminates the potential problem of freezing the heating mediumcomponents in the water circuit where the user has had to drain thesystem down during the winter time where there is no usage of hot waterfrom the cylinder in the places like holiday homes, mobile homes orothers for example.

In the present invention the said compressor can be mounted on a platewith selected anti-vibration mounts that generally accompany acompressor. Additionally the main chassis can be mounted with additionalanti-vibration mounts to act as twin layer anti-vibration method toreduce any further possible vibration that may travel to the mainchassis of the invention.

When the invention is installed on a wall, additional externalanti-vibration mounts are supplied to be installed on the back of theinvention between the invention and the wall. The back plate ofinvention has been uniquely designed to receive these mounts. Having theanti-vibration mounts on the back of the invention with these twin-layeranti-vibrations on the bottom of the compressor within the inventionremoves any potential vibration travelling into the building.

There are several air to water heat pumps in the market and most of themneed a circulating pump to circulate the water from the cylinder to theheat pump. These pumps typically are set by the controller to run beforethe compressor in the heat pump starts.

Since the present invention has a compressor and a circulating pump thisinvention includes a controller but uniquely it allows the circulatingpump to run before the compressor starts and after the compressor stopswith time delay on/off function.

This delay function is significant as it allows the water flowing thoughthe heat exchanger with a circulating pump to remove any residual heatleft in the condenser before the compressor operates which starts thecompressor smoothly thereby increasing the compressor life.

This invention can have both functions such as delay on and delay off orcan have a single function. This function can be achieved eitherelectronically or mechanically.

This invention uses the evaporator to absorb the heat from theenvironment which either can either be a thermodynamic panel or fin-tubeevaporator with or without forced air circulation.

These inventions also incorporate in its design a thermodynamicevaporator panel that can be used as single or multiples depending onthe application and the location. This present invention allowsoperating the two panels in different modes. For example during thewinter period both panels can be used to extract the heat in the designand in the summer time it can be optionally selected that only one panelcan be used to extract the heat.

Functionality of the dual mode with two panels can be achieved by use ofthe solenoid valve 14 which can be uniquely operated and controlled by acontrolling device as a part of the invention.

Where the evaporator is a fin-tube heat exchanger a fan is used as partof the invention. The fan can be controlled by the controlling device 18which can be an electronic or mechanical device.

If the fin-tube heat exchanger is used as evaporator this inventionallows installation outdoors, typically outside the wall of the buildingas per FIG. 6 with fan controlling devices

This invention also allows the evaporator (Fin-tube heat exchanger) tobe integrated within the main unit with a fan (FIG. 7). When thefin-tube evaporator is used as an integral part of the main unit the fanwill have control device to handle different air volume and thedifferent static pressure.

The unique feature of having control device for the fan will allow themain invention to be installed in various locations of the building witha duct to push the cold air out (See FIG. 7 a-7 c).

If the installation is as per FIG. 7 a with shorter ducting then the fancontrol device can be set to allow the fan to run in lower speed to keepthe optimum performance of the whole invention. If the installation isas in FIG. 7 b with long ducting then the fan control can be set toallow the fan to higher speed level to keep the same performance as thesmaller ducting.

1. A heat exchange system comprising: a compressor to compress arefrigerant, a first condenser heat exchanger to which the compressedrefrigerant is supplied and at which heat is transferred from therefrigerant to water from a hot water cylinder; an expansion valve thatreceives cooled liquid refrigerant from the first heat exchanger; athermodynamic panel including a second heat exchanger heat that receivescool refrigerant from the expansion valve and is in thermalcommunication with an environmental heat source.
 2. A heat exchangesystem as claimed in claim 1 wherein the condenser heat exchanger hastwo flow paths in thermal communication, a first flow path forrefrigerant and a second flow path for water from the hot watercylinder.
 3. A heat exchange system as claimed in claim 2 wherein wateris pumped from the hot water cylinder through the second flow path andback to the cylinder by a circulating pump.
 4. A heat exchange system asclaimed in claim 1 wherein the condenser heat exchanger is a block orthermally conductive material with circuitous flow paths formed therein.5. A heat exchange system as claimed claim 1 which also includes one ormore of and accumulator or receiver, a filter, a drier, a sight glass ormoisture indicator.
 6. A heat exchange system as claimed in claim 3wherein the circulating pump operates with a with time delayfunctionality.
 7. A heat exchange system as claimed in claim 1 whereinthe condenser heat exchanger is orientated in a way to self-drain thewater therefrom as required.
 8. A heat exchange system as claimed inclaim 1 wherein an air bleed valve assembly is provided to remove theair from the system.
 9. A heat exchange system as claimed in claim 1wherein a solenoid valve or actuator and control device open/close therefrigeration circuit in a second panel depending on the conditions. 10.A heat exchange system as claimed in claim 1 wherein the second heatexchanger is a fin-tube evaporator installed outdoor or as part of acombined unit.
 11. A heat exchange system as claimed in claim 10,wherein a fan is provided to pass air over the evaporator.
 12. Heatexchanger apparatus for use in a system as claimed in claim 1 comprisingthe compressor; the first condenser heat exchanger; an expansion valvethat receives cooled liquid refrigerant from the first heat exchanger;means to pump water to and from the hot water cylinder through the firstcondenser heat exchanger; and means to connect to the thermodynamicpanel in thermal communication with an environmental heat source. 13.Heat exchanger apparatus as claimed in claim 12 in which all thecomponents are mounted inside a single unit.
 14. Heat exchangerapparatus as claimed in claim 12, wherein the compressor is mounted insuch a way as to absorb or minimise vibration or noise.
 15. Heatexchanger apparatus as claimed in claim 13, wherein the single unit ismounted in such a way as to absorb or minimise vibration or noise.